The National Weather Service says has extended a high surf advisory until 4 p.m. today for north and west shores of Kauai, Niihau, Oahu, Molokai and Maui.
Surf peaked early Saturday morning at warning levels of up to 30 feet, but the wave heights are expected to diminish late this afternoon.
In the meantime, north-facing shores of islands covered by the advisory are expected to get 12- to 18-feet waves, while west shores should see 8- to 12-foot surf.
The weather service says the swell is bringing strong breaking waves and shore break and strong currents, making swimming difficult and dangerous.
Beachgoers are urged to heed advice given by ocean safety officials and exercise extreme caution.
A moderate northwest swell is expected Monday, followed by another swell arriving Thursday that may again bring advisory-level or even warning-level surf along north and west facing shores from Thursday night into Friday.